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(11)

EP 3 649 293 A1

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(43) Date of publication: 13.05.2020 Bulletin 2020/20 (21) Application number: 18847895.2 (22) Date of filing: 21.08.2018

(51) International Patent Classification (IPC):  E01F 9/623(2016.01) E04H 12/22(2006.01) E01F 15/14(2006.01) E02D 5/60(2006.01) (86) International application number: PCT/US2018/047277 (87) International publication number: WO 2019/040466 (28.02.2019 Gazette 2019/09)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 25.08.2017 US 201762550192 P (71) Applicant: Pepco Holdings LLC Washington, DC 20001 (US)	(72) Inventors: SHI, Haijian Arlington, VA 22203 (US) STEEG, Richard Avondale, PA 19311 (US) (74) Representative: Rupprecht, Kay  Meissner Bolte Patentanwälte Rechtsanwälte Partnerschaft mbB Widenmayerstraße 47 80538 München 80538 München (DE)